NFL Media Insider Ian Rapoport reported that the Lions are signing the defensive tackle to a one-year deal worth $1.6 million, with a chance to make $2.25 million based on play-time incentives, per a source involved in the deal.
The Detroit Free Press first reported Walker was flying to Detroit in hopes of re-signing.
Walker missed 12 games in his first season with the Lions, suffering a broken leg and dislocated ankle. Walker tweeted out a video Wednesday of himself doing drills, indicating he's close to being fully recovered from October surgery.
Walker was set to become an unrestricted free agent.
The one-year contract also allows Walker, who showed promise in New Orleans in 2014 and his four games last year, to hit the free-agent market again next offseason. With a big year, the 25-year-old lineman could then cash in on a long-term deal.